Integrated circuit (IC) chip miniaturization is an important development direction in the semiconductor industry. Thus, all the leading semiconductor manufacturers around the world have been focusing on the research and development of process miniaturization in the hope of integrating different digital logics, memories, and analog circuits into single chips, so as to greatly increase the operating speed and the functionality of circuits and reduce the product cost. A logic gate is an essential block in an IC. The circuit of a conventional logic gate is composed of metal oxide semiconductor (MOS) transistors. By reducing the surface area taken by each logic gate, the product density can be increased and the product cost can be reduced.